An active tactile (haptic) feedback is a desirable property for electronic products with touch screens. Presently available actuators are not quite adequate for providing such haptic feedback in the electronic devices with touch screens. Especially this relates to portable communication devices, requiring small dimensions and low operating voltage of such actuators. These conditions are not met by, e.g., piezo actuators requiring high operating voltages, or by the electromagnetic actuators which are bulky. Moreover, minimizing energy consumption requires leaving an air gap between a cover and a display (screen) if piezo or electromagnetic actuators are used for tactile feedback which prevents proper sealing of the screen in the electronic devices. To resist water and dust coming to the electronic device when the screen moves is a necessity in practice. In theory it is possible to make a separate flexible sealing with piezo and electromagnetic actuators but this will potentially reduce touch areas of the screen and will complicate the design.
Electrostrictive polymers offer energy efficient actuation with much larger strain than other technologies mentioned above. The electrostrictive polymers change shape tens of times more than piezo materials which comparable voltages applied. Furthermore, electrostrictive polymers have a high flexibility, elasticity, and can form complicated shapes. A combination of these properties creates an opportunity for combining sealing, gluing and shock absorbing functions with tactile actuation when electrostrictive polymers are used.